Reducing nitrous oxide emissions by changing N fertiliser use from calcium ammonium nitrate (CAN) to urea based formulations

The accelerating use of synthetic nitrogen (N) fertilisers, to meet the world's growing food demand, is the primary driver for increased atmospheric concentrations of nitrous oxide (N2O). The IPCC default emission factor (EF) for N2O from soils is 1% of the N applied, irrespective of its form. However, N2O emissions tend to be higher from nitrate-containing fertilisers e.g. calcium ammonium nitrate (CAN) compared to urea, particularly in regions, which have mild, wet climates and high organic matter soils. Urea can be an inefficient N source due to NH3 volatilisation, but nitrogen stabilisers (urease and nitrification inhibitors) can improve its efficacy. This study evaluated the impact of switching fertiliser formulation from calcium ammonium nitrate (CAN) to urea-based products, as a potential mitigation strategy to reduce N2O emissions at six temperate grassland sites on the island of Ireland. The surface applied formulations included CAN, urea and urea with the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) and/or the nitrification inhibitor dicyandiamide (DCD). Results showed that N2O emissions were significantly affected by fertiliser formulation, soil type and climatic conditions. The direct N2O emission factor (EF) from CAN averaged 1.49% overall sites, but was highly variable, ranging from 0.58% to 3.81. Amending urea with NBPT, to reduce ammonia volatilisation, resulted in an average EF of 0.40% (ranging from 0.21 to 0.69%)-compared to an average EF of 0.25% for urea (ranging from 0.1 to 0.49%), with both fertilisers significantly lower and less variable than CAN. Cumulative N2O emissions from urea amended with both NBPT and DCD were not significantly different from background levels. Switching from CAN to stabilised urea formulations was found to be an effective strategy to reduce N2O emissions, particularly in wet, temperate grassland.

Early childhood caries in Indigenous communities: A joint statement with the American Academy of Pediatrics

The oral health of Indigenous children of Canada (First Nations, Inuit and Métis) and the United States (American Indian and Alaska Native) is a major child health issue. This is exemplified by the high prevalence of early childhood caries (ECC) with resulting adverse health effects, as well as high rates and costs of restorative and surgical treatments under general anesthesia. ECC is an infectious disease that is influenced by multiple factors, including socioeconomic determinants, and requires a combination of approaches for improvement. The present statement includes recommendations for oral health preventive and clinical care for young infants and pregnant women by primary health care providers, community-based health promotion initiatives, oral health workforce and access issues, and advocacy for community water fluoridation and fluoride varnish program access. Further community-based research on the epidemiology, prevention, management and microbiology of ECC in Indigenous communities would be beneficial.

Raman analysis of caraway (Carum carvi L.) single fruits. Evaluation of essential oil content and its composition

FT-Raman spectroscopy was applied for in situ analysis of single and intact fruits obtained from a diverse caraway (Carum carvi L.) collection. The Raman spectra showed characteristic bands that could be assigned to lignin, unsaturated fatty acids, and polysaccharides. Additionally, the essential oil composition was determined by gas chromatography (GC), which showed a great variation in carvone and limonene content among accessions obtained from European botanical gardens as well as advanced breeding materials. GC data and information obtained from Raman measurements were correlated and allowed development of calibration models for essential oil yield and carvone and limonene content (R(2) = 74%, 81%, and 75%, respectively). The congruence between results obtained by both techniques indicates FT-Raman spectroscopy to be a valuable screening tool for quality control and selection of fruits with desired essential oil composition, which can be performed without fruit destruction.

Title VII funding is associated with more family physicians and more physicians serving the underserved

Title VII funding of departments of family medicine at U.S. medical schools is significantly associated with expansion of the primary care physician workforce and increased accessibility to physicians for the residents of rural and underserved areas. Title VII has been successful in achieving its stated goals and has had an important role in addressing U.S. physician workforce policy issues.

Factors influencing the career choices of physicians trained at Yale-New Haven Hospital from 1929 through 1994

PURPOSE

To examine factors that influenced, positively or negatively, the specialty career choices of physicians trained at Yale-New Haven Hospital (YNHH) from 1929 to 1994.

METHOD

The authors sent questionnaires to 4,888 physicians who had trained or were training in YNHH-sponsored residency programs. The physicians rated 36 factors posited to be influenced in career choice on a seven-point Likert scale from very negative to very positive. The authors compared the means of each factor's ratings by decade of medical school graduation.

RESULTS

The most positively rated influences were similar in each decade from the 1920s to the 1990s. These influences shared characteristics of intellectual curiosity ("intellectual content of the specialty" and "challenging diagnostic problems"), altruism ("interest in helping people" and "opportunity to make differences in people's lives"), and personal identity ("consistent with personality" and "possess the required skill or ability"). Negative factors, such as "demands on time and effort," "stress in the field," and "malpractice costs," were also consistently rated throughout the decades.

CONCLUSION

The reasons that physicians choose certain specialty careers have not changed significantly over the past 65 years despite all the changes that have occurred in medicine. Physicians continue to seek professional opportunities that are viewed as intellectually challenging and of benefit to others.